The pericardial effusion pattern on phase images.

Abstract

The effect of pericardial effusion on phase images of gated studies was investigated. Twenty-six patients with suspected or known pericardial effusion were correlated with echocardiography and/or clinical and other laboratory data to ascertain the presence and size of effusion. The phase image pattern and parameters were compared to the results previously obtained in seven normal patients, and in 26 patients with documented regional wall motion abnormalities but no evidence of pericardial effusion. The phase pattern was graded into five categories: typical (IV) (wide histogram, well defined concentric convex pattern, progressive delay toward the inferolateral area, identifiable also over the right ventricle); less pronounced (III); atypical (II); ill defined changes (I); and normal (0). Group L (large pericardial effusion): four of six had pattern (IV) and the left ventricular histogram showed abnormal parameters. These patients had large free effusions in the pericardial sac and none had regional wall motion abnormalities. Two of six had pattern (III) and (II) but also had ancillary pericardial pathology and/or decreased ejection fraction. Group M (moderate pericardial effusion), S (small pericardial effusion), and A (absent pericardial effusion, but not normal) had variable phase images and numeric parameters. After therapeutic drainage of pericardial fluid two patients changed pattern from IV and III to 0 and a third from III to I. Category IV pattern is 100% specific for pericardial effusion; the combination of category IV or III is 87.5% specific and 61% sensitive for large and moderate pericardial effusion.(ABSTRACT TRUNCATED AT 250 WORDS)